The present invention relates generally to medical equipment, and more particularly, to an automated apparatus for filling unit dose, disposable syringes with one or more medications that are each stored in a vial.
Disposable syringes are in widespread use for a number of different types of applications. For example, syringes are used not only to withdraw a fluid (e.g., blood) from a patient but also to administer a medication to a patient. In the latter, a cap or the like is removed from the syringe and a unit dose of the medication is carefully measured and then injected or otherwise disposed within the syringe.
As technology advances, more and more sophisticated, automated systems are being developed for preparing and delivering medications by integrating a number of different stations, with one or more specific tasks being performed at each station. For example, one type of exemplary automated system operates as a syringe filling apparatus that receives user inputted information, such as the type of medication, the volume of the medication and any mixing instructions, etc. The system then uses this inputted information to disperse the correct medication into the syringe up to the inputted volume.
In some instances, the medication that is to be delivered to the patient includes more than one pharmaceutical substance. For example, the medication can be a mixture of several components, such as several pharmaceutical substances.
By automating the medication preparation process, increased production and efficiency are achieved. This results in reduced production costs and also permits the system to operate over any time period of a given day with only limited operator intervention for manual inspection to ensure proper operation is being achieved. Such a system finds particular utility in settings, such as large hospitals, including a large number of doses of medications have to be prepared daily. Traditionally, these doses have been prepared manually in what is an exacting but tedious responsibility for a highly skilled staff. In order to be valuable, automated systems must maintain the exacting standards set by medical regulatory bodies, while at the same time simplifying the overall process and reducing the time necessary for preparing the medications.
Because syringes are often used as the carrier means for transporting and delivering the medication to the patient, it is advantageous for these automated systems to be tailored to accept syringes. However, the previous methods of dispersing the medication from the vial and into the syringe were very time consuming and labor intensive. More specifically, medications and the like are typically stored in a sealed vial. As shown in FIGS. 1 and 1a, a conventional vial 10 is formed of a body 20 (i.e., glass) and is sealed with a membrane (septum) 30 across the open end 22 of the body 20. The membrane 30 can be formed of any type of material that is typically used in this setting for sealing a container (e.g., vial 10) yet at the same time permit a user to puncture or pierce the membrane 30 with an instrument to gain access to the inside of the container. In one exemplary embodiment, the membrane 30 is formed of a rubber material that can be easily stretched across the open end 22 while still providing the necessary seal.
The membrane 30 is securely held in place across the open end 22 by a retainer ring 40 that is itself securely attached to the body 20. The retainer ring 40 circumferentially surrounds a neck 21 formed at the open end 22 and includes an upper section 42 that seats against an upper surface the membrane 30 and a lower section 44 that engages the body 20 underneath the neck 21. The retainer ring 40 is open in a middle section 23 thereof such that when the retainer ring 40 is securely attached to the body 20, the retainer ring 40 holds the stretched membrane 30 in place with the membrane 30 being visible in the open middle section of the retainer ring 40. The retainer ring 40 can be attached to the body 20 using any number of conventional techniques, including a crimping process, so long as the retainer ring 40 securely holds the membrane 30 such that a seal results between the open end 22 and the membrane 30.
A safety cap 50 is securely attached to the vial 10 to cover the exposed membrane 30 and further seal the open end 22 of the vial body 20. The safety cap 50 is typically formed of a light, disposable material, such as a plastic, and is attached at the end 22 in a tamper proof manner. For example, the safety cap 50 is attached so that once it is removed, it can not be reattached to the vial body 22. Thus, a vial that does not contain a safety cap 50 is easily recognizable and indicates that either (1) the safety cap 50 has previously been removed and medication in the vial 20 has been withdrawn, (2) the safety cap 50 was not properly attached and has accidently become displaced, (3) the vial 50 has been tampered with, etc. In any event and unless the exact history of the particular vial is know, any vial that is missing a safety cap 50 is ordinarily discarded and not used.
The safety cap 50 is a solid member that extends completely across the exposed portion of the membrane 30 and, preferably, the peripheral edges of the safety cap 50 are downwardly curved so that the peripheral edges overlap the outer peripheral edges of the retainer ring 40. The safety cap 50 contains features that permit it to be attached to the retainer ring 40. In one exemplary embodiment, the retainer ring 40 has a plurality of bosses 60 that extends upwardly from the retainer ring 40 near the inner edge of the retainer ring 40. When the safety cap 50 is attached to the retainer ring 40, the plurality of bosses 60 seats within complementary openings formed in the safety cap 50 so as to frictionally couple the two parts together. For example, the safety cap 50 can be injected molded around the retainer ring 40, thereby resulting in the formation of the safety cap 50 around the plurality of bosses 60. The connection between the bosses 60 and the safety cap 50 represents a weakened section which breaks when force is applied to the safety cap 50 in an appropriate direction. This results in the safety cap 50 being easily removed, while at the same time provides a tamper proof arrangement because, once the weakened section is broken and the safety cap 50 is free, the safety cap 50 can not later be reattached to the retainer ring 40 or any other part of the vial 10.
It will be understood that the parts of the vial 10 of FIGS. 1 and 1a are merely exemplary in nature and the many different tamper proof vial constructions are available. The common elements are that the vials each contain a membrane and the safety cap is easily removable but at the same time provides further protection of the membrane and also serves as an indicator of whether the vial has been used.
In conventional medication preparation, a trained person retrieves the correct vial from a storage cabinet or the like, confirms the contents and then removes the safety cap manually. This is typically done by simply popping the safety cap off with ones hands. Once the safety cap is removed, the trained person inspects the integrity of the membrane and cleans the membrane. An instrument, e.g., a needle, is then used to pierce the membrane and withdraw the medication contained in the vial. The withdrawn medication is then placed into a syringe to permit subsequent administration of the medication from the syringe. Often, the membrane is first pierced with an instrument for injecting a diluent into the medication prior to withdrawal of the medication. This is a very time and labor intensive task and what is needed in the art and has heretofore not been available is a system and method for automating the medication preparation process and more specifically, an automated system and method for retrieving a drug vial, removing the safety cap, and cleaning the vial just prior to use.
The present invention provides an automated safety cap removal mechanism for an automated medication preparation system. The mechanism includes an automated gripping device for securely holding and transporting a vial containing the medication to and from a first station and a cap removal device for removing a safety cap of the vial in a just-in-time for use manner. The cap removal device being located at the first station. By providing a just-in-time for use safety cap removal mechanism, the labor intensive task of removing safety caps can be incorporated into an automated medication preparation system.
In one embodiment, the cap removal device includes a support member and a pivotable member coupled to the support member. The pivotable member is biased in a first direction such that when the automated gripping device delivers the vial to the first station, the pivotable member engages the safety cap which is then removed from the vial by moving the vial in a second direction as it is held by the automated gripping device. The pivotable member thus acts as a pry bar to cause removal of the safety cap.
In another embodiment, the cap removal device includes a wedge element for reception between the safety cap and a body of the vial such that when the automated gripping device delivers the vial to the first station, the wedge element is received between the safety cap and the vial body. The safety cap is then removed from the vial by moving the vial in a second direction as it is held by the automated gripping device.
In yet another embodiment, the cap removal device includes a rotatable member having first and second gripping sections. Each of the first and second gripping sections has openable and closeable decapper elements that are controlled by a control unit. The safety cap is removed by disposing the safety cap between the opened decapper elements which are then closed prior to moving the vial in a second direction as the safety cap is gripped by the decapper elements. This results in the safety cap being removed.
In another aspect, the mechanism includes a detector (e.g., a sensor) for sensing the removal of the safety cap from the vial. The detector is in communication with a control unit that also communicates with the automated gripping device for moving the automated gripping device to select locations. The detector generates a detection signal upon sensing that the safety cap has been removed. This detection signal instructs the control unit to proceed with moving the decapped vial to either a next station or to a location where a next operation is performed.
The present application also provides a method for just-in-time removal of a safety cap from a drug vial. The method includes the steps of first moving the drug vial onto a deck of an automated medication preparation system. The drug vial has the safety cap affixed over an opening thereof. Second, the drug vial is gripped against movement, and third a step is performed for removing the safety cap while gripping the drug vial.
Further aspects and features of the exemplary automated safety cap removal mechanism disclosed herein can be appreciated from the appended Figures and accompanying written description.